package com.guoheng.hazard.manager.download;


import com.guoheng.hazard.common.base.Result;
import com.guoheng.hazard.manager.log.LogManager;
import com.guoheng.hazard.sys.model.dto.DownloadDTO;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.validation.constraints.NotBlank;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * 类功能描述:　DownloadManager
 *
 * @author fbl
 * @date 2019-10-15 14:56
 */
@Component
public class DownloadManager {

    private static final Logger LOG = LoggerFactory.getLogger(LogManager.class);

    @Value("${spring.servlet.multipart.location}")
    private String savePath;


    /**
     * 从网络Url中下载文件
     *
     * @param downloadDTO
     * @throws IOException
     */
    public Result downLoadFromUrl(DownloadDTO downloadDTO) throws IOException {
        @NotBlank String downloadUrl = downloadDTO.getDownloadUrl();
        @NotBlank String fileName = downloadDTO.getFileName();
        URL url = new URL(downloadUrl);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        // 设置超时间为3秒
        conn.setConnectTimeout(3 * 1000);

        // 防止屏蔽程序抓取而返回403错误
        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
        // 得到输入流
        InputStream inputStream = conn.getInputStream();
        // 获取自己数组
        byte[] getData = readInputStream(inputStream);

        // 文件保存位置
        File saveDir = new File(savePath);
        if (!saveDir.exists()) {
            saveDir.mkdir();
        }
        File file = new File(saveDir + File.separator + fileName);
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(getData);
        if (fos != null) {
            fos.close();
        }
        if (inputStream != null) {
            inputStream.close();
        }

        System.out.println("info:" + url + " download success");
        return Result.success();

    }

    /**
     * 从输入流中获取字节数组
     *
     * @param inputStream
     * @return
     * @throws IOException
     */
    public static byte[] readInputStream(InputStream inputStream) throws IOException {
        byte[] buffer = new byte[1024];
        int len = 0;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        while ((len = inputStream.read(buffer)) != -1) {
            bos.write(buffer, 0, len);
        }
        bos.close();
        return bos.toByteArray();
    }
}
